The daily Sicha is a short Sicha of the Rebbe chosen by the "Daily Sicha" system for each day (week) of the year, with instruction in the work of G-d or a specific commentary, etc. Related to current affairs - Chitas or Rambam lesson, Yoma Depgra or a specific topic in general.
The short length of each "Daily Sicha", about ten minutes, allows everyone to find the time of day to listen to the conversation. This allows:

The instructions in the Rebbe's Sichos "Living with the Rebbe" by hearing a Sicha from the Rebbe every day!

Strengthening the connection to our Rebbe by "studying his teachings"
Strengthening the unity between Anash and Temimim all over the world by hearing the same conversation of the Rebbe every day
And the main thing - the acceleration of the true and complete redemption that then we will merit to hear the sounds "a new Torah from the mouth of Moshiach"